This invention relates in general to an apparatus for treating flowing working gases and in particular to a new and useful device particularly for reducing the noise of operation of devices such as internal combustion engines, air operated tools, etc. and further to increase the flow efficiency of such devices.
The present invention is an improvement over that disclosed and claimed in the above mentioned patent primarily in respect to the construction in which a check valve is employed at the discharge of the working gases which is effective to prevent back flow into the operating device and thus reduce its noise and also in respect to the details of construction of such a check valve and to an improved method of operating a tool to prevent noise particularly during turnoff.